Tracing system for analyzing an information distribution route by automatically gathering distribution histories from systems which the information is routed through

ABSTRACT

An information processing system of the present invention records information on distribution when information is distributed so that an information distribution route is traced later. In the information processing system, when information held in an information holding section is distributed from an information distribution section to a different information intervention system, a distribution sensing section senses it and records its distribution history in a distribution history holding section. When an information tracing instruction is given, a history collection section fetches distribution histories related to the information to be traced from the distribution history holding section, detects the destination, and instructs the destination information intervention system to trace the information. In response to the instruction, history information is collected from the different information intervention system and is stored in a collected history holding section. A tracing analysis section analyzes the collected history information and displays the distribution route, etc., on a tracing result display section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an information processing method and aninformation processing system capable of tracing distributioninformation of an information distribution route, distribution range,distribution amount, etc.

2. Description of the Related Art

By the digital information technology development and the informationhighway initiative and the like, it will be soon accomplished that allinformation is digitalized and distributed through networks.Distribution of various pieces of information such as images, movingpictures, voice, and programs as well as text information has alreadybegun through network media such as internets and personal computercommunication. Although information originators or issuers and receiversare distinguished clearly from each other with information media likeconventional broadcasting, in such a system, all users may be bothinformation originators (issuers) and receivers. Therefore, anyone canreadily distribute various pieces of information in various forms.Digitalized information, which has a feature of easy copying, isdistributed via a number of persons; it is distributed among the userswho copy and redistribute the information, and the informationdistribution range and speed will be accelerated.

Under such circumstances, a situation in which once information is leftfrom a person, how it is passed to and used by what person is unknownoccurs. Each person may want to know whether or not once distributedinformation has been passed to his or her intended person, what pointthe information has been distributed to on the distribution route, whatroute the information has been distributed through, etc. Further,recently, programs into which computer viruses are mixed, informationcontaining a violation of privacy, and the like have often beendistributed illegally without recognition. When such illegal informationis distributed, a demand for specifying the originator or issuer and thedistribution route of the information also occurs. However, in theconventional art, such demands cannot fully be solved and some demandsare only solved.

For example, in an electronic mail communication network described inUnexamined Japanese Patent Publication (kokai) No. Hei 4-268849, at thenode receiving electronic mail, information concerning the originatorname and passed-through node added to the received electronic mail canbe compared with information concerning the network configuration heldin the node to see if the electronic mail originator name is false.Further, in transfer of electronic mail, the transmitter preparestransmission and reception logs together with information to be sent tothe receiver and transfers both as a unit to the receiver.

However, in the electronic mail communication network, thepassed-through node route when information is transmitted from one userA to another B is only recorded and when the information is furthertransmitted from user B to user C, user A information is not left. Thus,the function cannot be used for tracing across the users. Since theelectronic mail communication network depends on a specific feature ofelectronic mail, for example, if information is simply copied from astorage of one person to a storage of another person, the route ofdistribution (in this case, copy) of the information is not recorded andthe distribution route of the information cannot be known later.Further, for example, when the transmitter wants to know what point hisor her transmitted information reaches at present, he or she cannottrace it.

In an office information processing system described in UnexaminedJapanese Patent Publication (kokai) No. Hei 5-63728, control informationindicating what processing can be performed after reception is added toelectronic mail and history information on operation performed onreceived mail is stored. By referencing the history information, thetransmitter can know whether or not transmitted electronic mail has beenprocessed, for example. However, in the system, what route theinformation has been distributed through cannot be known although theoriginator of received electronic mail can be known. Like theabove-mentioned electronic mail system, the office informationprocessing system does not consider any distribution route other thanthe electronic mail system. Thus, in the office information processingsystem, the distribution route of received information cannot be known.

Further, in an electronic document preparation/approval system with anelectronic certification function described in Unexamined JapanesePatent Publication No. Hei 2-297288, certification data created by acertification process at approval is registered in a certificationlogging file, thereby enabling a document approval state to be traced.Since the electronic document preparation/approval system enables theapproval requester to know the current approval state, even if adocument is distributed to a person who does not perform an approvalprocess, the fact cannot be known. As with the electronic mailcommunication network, if information not related to approval is simplycopied from a storage of one person to a storage of another person, theroute of distribution (in this case, copy) of the information is notrecorded and the distribution route of the information cannot be knownlater.

As we have discussed, without using a special system such as theelectronic mail or approval system, when various kinds of informationare distributed by various methods through various persons, oncedistributed information cannot be traced to its distribution route andwhen illegal information is distributed, the originator (issuer) anddistribution route of the information cannot be located either.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an informationprocessing method and an information processing system for recordinginformation on distribution when information is distributed, therebyenabling an information distribution route to be traced later.

An information tracing system of the present invention is comprised of:distribution sensing unit for sensing information distribution from afirst information processing system as an information distributionsource to a second information processing system as an informationdistribution destination; a plurality of distribution history storingunit for storing histories related to information distribution sensed bythe distribution sensing unit; history acquiring unit for acquiring thehistories stored in other distribution history storing unit in responseto the history stored in one of the distribution history storing unit;and analyzing unit for analyzing an information distribution route inresponse to the histories acquired by the history acquiring unit.

According to the present invention, information distribution from adistribution source to a destination is sensed, and informationconcerning distribution of the sensed information is stored. Informationconcerning any other related distribution is acquired based on theinformation concerning one distribution, and a distribution route isanalyzed based on the acquired distribution information. Thedistribution route is a concept also containing the informationtransmission source, the transmission route, the distribution range, thedistributed information amount, etc., whereby distribution informationof information distribution, distribution route, distribution range,distribution amount, etc., can be traced later. At this time, the routecan also be traced in the information transfer, direction from theinformation transmission source and the information transfer route canalso be traced from the information reception party to the transmissionsource. The route in the information transfer direction or toward thetransmission source can also be traced at an intermediate point of thetransfer route.

BRIEF DESCRIPTION OF THE DRAWING

In the accompanying drawings:

FIG. 1 is block diagrams to show a first embodiment of an informationprocessing system of the invention;

FIG. 2 is an illustration of an example of the format of information inthe first embodiment of the information processing system of theinvention;

FIG. 3 is a hardware block diagram to show an example for providing thefirst embodiment of the information processing system of the invention;

FIG. 4 is an illustration of an example of information flows in thefirst embodiment of the information processing system the invention;

FIG. 5 is a flowchart to show an example of processing in a sourceinformation intervention system when information is distributed in thefirst embodiment of the information processing system of the invention;

FIG. 6 is a flowchart to show an example of processing in a destinationinformation intervention system when information is distributed in thefirst embodiment of the information processing system of the invention;

FIG. 7 is an illustration of an example of the information distributionoperation in the first embodiment of the information processing systemof the invention;

FIG. 8 is an illustration of an example of distribution histories heldin a distribution history holding section in the first embodiment of theinformation processing system of the invention;

FIG. 9 is an illustration of an example after information distributionin the first embodiment of the information processing system of theinvention;

FIG. 10 is a flowchart to show an example of processing of a historycollection section when information is traced in an informationintervention system which starts information tracing processing in thefirst embodiment of the information processing system of the invention;

FIG. 11 is a flowchart to show an example of processing of the tracinganalysis section when information is traced in the informationintervention system which starts information tracing processing in thefirst embodiment of the information processing system of the invention;

FIGS. 12 is a flowchart to show an example of processing of a historycollection section when information is traced in any other informationintervention system than the information intervention system whichstarts information tracing processing in the first embodiment of theinformation processing system of the invention;

FIGS. 13 is a flowchart (continued) to show an example of processing ofa history collection section when information is traced in any otherinformation intervention system than the information intervention systemwhich starts information tracing processing in the first embodiment ofthe information processing system of the invention;

FIG. 14 is an illustration of an example of the contents of thecollected history holding section in the first embodiment of theinformation processing system of the invention;

FIG. 15 is an illustration of an example of display of a tracing resultdisplay section in the first embodiment of the information processingsystem of the invention;

FIG. 16 is an illustration of an example of an information flow in asecond embodiment of the information processing system of the invention;

FIG. 17 is an illustration of an example of the information distributionoperation in the second embodiment of the information processing systemof the invention;

FIG. 18 is an illustration of an example after information distributionin the second embodiment of the information processing system of theinvention;

FIG. 19 is an illustration of an example of display of a tracing resultdisplay section in the second embodiment of the information processingsystem of the invention;

FIG. 20 is an illustration of an example of an information flow in athird embodiment of the information processing system of the invention;

FIG. 21 is an illustration of an example after information distributionin the third embodiment of the information processing system of theinvention;

FIG. 22 is an illustration of an example of display of a tracing resultdisplay section in the third embodiment of the information processingsystem of the invention;

FIG. 23 is block diagrams to show a fourth embodiment of the informationprocessing system of the invention;

FIG. 24 is an illustration of an example of an information flow in thefourth embodiment of the information processing system of the invention;

FIG. 25 is an illustration of an example after information distributionin the fourth embodiment of the information processing system of theinvention;

FIG. 26 is an illustration of an example of the contents of a collectedhistory holding section in the fourth embodiment of the informationprocessing system of the invention;

FIG. 27 is an illustration of an example of distribution route displayof a tracing result display section in the fourth embodiment of theinformation processing system of the invention;

FIG. 28 is an illustration of an example of preparation process displayof the tracing result display section in the fourth embodiment of theinformation processing system of the invention;

FIG. 29 is a block diagram to show the fifth embodiment of theinformation processing system of the invention;

FIG. 30 is an illustration of an example of the format of information inthe fifth embodiment of the information processing system of theinvention;

FIG. 31 is a block diagram to show a sixth embodiment of the informationprocessing system of the invention;

FIG. 32 is an illustration of an example of information flows in thesixth embodiment of the information processing system of the invention;

FIG. 33 is an illustration of an example of display of a tracing resultdisplay section in the sixth embodiment of the information pressingsystem of the invention;

FIG. 34 is an illustration to show an example of the format ofinformation when information is provided with a distribution history ina seventh embodiment of the information processing system of theinvention;

FIG. 35 is an illustration of an example of the information distributionoperation when information is provided with a distribution history inthe seventh embodiment of the information processing system of theinvention;

FIG. 36 is an illustration to show an example of the format ofinformation when an information medium is provided with a distributionhistory in the seventh embodiment of the information processing systemof the invention;

FIG. 37 is an illustration of an example of the information distributionoperation when an information medium is provided with a distributionhistory in the seventh embodiment of the information processing systemof the invention; and

FIG. 38 is an illustration of an example of the information distributionoperation in an eighth embodiment of the information processing systemof the invention.

PREFERRED EMBODIMENTS OF THE INVENTION

Referring now to the accompanying drawings, preferred embodiments of thepresent invention will be described.

First Embodiment:

FIG. 1 is block diagrams to show a first embodiment of an informationprocessing system of the invention. In the figure, numeral 1 designatesan information intervention system; 11, an information holding section;12, an information distribution section; 13, a system label section; 14,a distribution sensing section; 15, a distribution history holdingsection; 16, a history collection section; 17, a collected historyholding section; 18, a tracing analysis section; and 19, a tracingresult display section.

The information intervention system 1, which intervenes in informationtransfer and distribution, has the information holding section 11, theinformation distribution section 12, the system label section 13, thedistribution sensing section 14, the distribution history holdingsection 15, the history collection section 16, the collected historyholding section 17, the tracing analysis section 18, and the tracingresult display section 19.

The information intervention system 1 mentioned in the invention refersto a system for intervening in information transfer in a broad sense;specifically, it contains not only a system dedicated to informationtransfer, such as a gateway in a network or an exchange in a telephonenetwork, but also a system resultantly distributing information, such asan information processing system like a workstation or personal computerconnected to a network. It also contains a mail server, etc., fordistributing electronic mail on a network. Further, it contains anelectronic information machine such as a disk drive for reading andwriting information storage media such as hard disk or floppy disk;information copying, etc., between information storage media or within asingle information storage medium corresponds to informationdistribution.

The information holding section 11 stores information processed by theinformation intervention system 1, for example, information to bedistributed or distributed. In fact, it is made of a memory or amagnetic disk unit.

The information distribution section 12 exchanges information with otherinformation intervention systems, whereby information can bedistributed. For example, it is made up of a network interface, a modem,etc., for transmitting and receiving information to and from otherinformation intervention systems via a network.

The system label section 13 holds a system identifier for uniquelyidentifying the information intervention system 1. The system identifieris given when the information intervention system is manufactured; itmay be inhibited from being changed later, or when the system isconstructed, a unique identifier may be given.

The distribution sensing section 14 always monitors to sense whether ornot the information distribution section 12 exchanges information withanother information intervention system. When the informationdistribution section 12 exchanges information, the distribution sensingsection 14 senses information on the exchange and records it in thedistribution history holding section 15 as a distribution historyrelated to information distribution. For example, if the informationdistribution section 12 is made of a network interface, the informationexchange can be sensed if the network interface is monitored. Theinformation to be sensed includes the information identifier oftransferred information, the associated transfer system identifier, thedistribution time of day, and the like are to be sensed. In addition,the source/destination user identifier, the information type, etc., maybe sensed and recorded. The distribution time of day may be specifiedwith a timer or clock contained in each information intervention system1.

The distribution history holding section 15 records distributionhistories related to information distribution sensed by the distributionsensing section 14. For example, it is made of an external storage suchas a magnetic disk unit or a memory. The held contents will be discussedlater.

When a tracing instruction for one information is issued, the historycollection section 16 reads the distribution histories related to thespecified information from the distribution history holding section 15,and sends an information tracing instruction to other informationintervention systems based on the distribution histories. Further, itreceives reports from the information intervention systems to which theinstruction was sent, and stores the reports in the collected historyholding section 17. If a tracing instruction is given from anotherinformation intervention system and information is traced, the historycollection section 16 returns the tracing result to the informationintervention system giving the tracing instruction. It can be made up ofa network, a telephone line, a modem, etc., for example. However, it isnot limited to them and any other means may be used if it can accomplisha similar purpose, needless to say. The history collection section 16may share a part of the configuration of the network interface, modem,etc., with the information distribution system 12.

The collected history holding section 17 stores the distributionhistories collected by the history collection section 16 from otherinformation intervention systems. The collected distribution historiesare stored together with the system identifiers of the systems fromwhich the histories are collected, which will be described in detaillater.

The tracing analysis section 18 analyzes the distribution historiescollected from other information intervention systems and stored in thecollected history holding section about the item specified by a commandof the user, etc. It analyzes various pieces of information ondistribution such as information transfer, distribution route,distribution range, etc., as to how information was distributed viawhich information intervention systems. A specific analysis algorithmwill be described later.

The tracing result display section 19 produces output such as display ofthe analysis result of the tracing analysis section 18 in the formatthat can be understood by the user, etc. In the embodiment, the tracingresult display section 19 is used for visualizing the analysis result ofthe trace information in the format that can be understood by humanbeings, but the invention is not limited to it. For example, if theanalysis result is used by a computer, etc., for performing automaticprocessing, the tracing result display section can be replaced withanother component.

FIG. 2 is an illustration of an example of the format of information inthe first embodiment of the information processing system of theinvention. As shown in the drawing, the information has an informationmain body and an information label section for holding an informationidentifier to identify the information. The information main body isinformation having essential meanings and contains various kinds ofinformation such as images, programs, texts, and moving pictures. Theinformation label section contains the information identifier touniquely identify the information. The information identifier may be anyif it can distinguish the information from any other information, suchas a label represented by a pair of machine name and file name as wellas such an identifier represented by digits, etc.

Although the information label section is used for holding only theinformation identifier in the embodiment, generally it may storeattributes concerning the information, such as the information creatorand creation date. In such a system charging for the service in responseto the use amount of information, information on the charge is alsostored in the information label section. If only the informationidentifier is stored in the information label section, it may beattached to the information main body without providing the informationlabel section. In any way, the information identifier or suchinformation stored in the information label section has no meaning if itis separated from the information main body. Thus, generally it isencrypted so as not to be separated at the distribution time, forexample.

FIG. 3 is a hardware block diagram to show an example for providing thefirst embodiment of the information processing system of the invention.In the figure, 31 and 32 designate networks; 33, a terminal; 34, aserver; 35, a gateway; 36, a CPU; 37, a disk; 38, an output unit; and39, an input unit. The example shown in FIG. 3 is made up of machinesconnected through some communication means, such as the terminals 33 ofworkstations, personal computers, etc., and the server 34 connectedthrough communication means such as the networks 31 and 32 and thegateway 35 for connecting the networks. The terminals 33 are made ofgeneral workstations, personal computers, etc., each of which consistsof a CPU 36, a disk 37, an output unit 38 such as a display, and aninput unit such as a keyboard and a mouse. The server 34 and the gateway35 are also general machines each consisting of a CPU 36, a disk 37,etc. The information intervention systems 1 can be related to all orsome of the machines shown in FIG. 3.

Next, the operation in the first embodiment of the informationprocessing system of the invention will be described. FIG. 4 is anillustration of an example of information flows in the first embodimentof the information processing system of the invention. It shows fourinformation intervention systems A-D and gives an example in whichinformation X is distributed from information intervention system A toinformation intervention system B from which the information X isdistributed to information intervention systems C and D.

The information intervention system A senses distribution of theinformation X to the information intervention system B and records itsdistribution history in the distribution history holding section 15.Likewise, the information intervention system B senses distribution ofthe information X to the information intervention systems C and D andrecords two distribution histories in the distribution history holdingsection 15.

When an instruction for tracing the distribution route of theinformation X is given in the information intervention system A, thedistribution history of the information X is fetched from thedistribution history holding section 15 of the information interventionsystem A and the information intervention system B to which theinformation X was distributed is instructed to trace the distributionroute of the information X. Upon reception of the instruction fortracing the distribution route of the information X from the informationintervention system A, the information intervention system B fetches thedistribution history of the information X from its distribution historyholding section 15 and instructs the information intervention systems Cand D to which the information X was distributed to trace thedistribution route of the information X. The information interventionsystems C and D, which do not hold the distribution history of theinformation X, return a message to the effect that the distributionhistory related to the information X does not exist to the informationintervention system A. The information intervention system B returns thedistribution histories recorded when the information X was distributedto the information intervention systems C and D to the informationintervention system A, whereby the information intervention system A canknow that the information X was distributed as shown in FIG. 4. Thus,the information intervention system A can analyze the distributionroute, distribution range, etc., of the information X.

A processing flow as described above will be described in detail. First,the information distribution operation will be described. FIG. 5 is aflowchart to show an example of processing in a source informationintervention system when information is distributed in the firstembodiment of the information processing system of the invention. Atstep S41, the source information intervention system assigns the systemidentifier of the destination information intervention system tovariable M-to and the information identifier of the information to bedistributed to variable X. Next, at step S42, the informationdistribution section 12 of the information intervention system Asearches for the information intervention system having the systemidentifier equal to that stored in the variable M-to on the network andestablishes a connection to the found information intervention system.At step S43, it reads the information having the information identifierequal to that stored in the variable X from the information holdingsection 11, and assigns the read information to variable InfoX. At stepS44, the information distribution section 12 distributes the informationstored in the variable InfoX to the information intervention systemhaving the system identifier stored in the variable M-to. At step S45,the distribution sensing section 14 senses the distribution process andrecords a set of (X, M-to, Time), where Time denotes the distributiontime of day, in the distribution history holding section 15 as adistribution history. The information distribution process in the sourceinformation intervention system is now complete.

FIG. 6 is a flowchart to show an example of processing in a destinationinformation intervention system when information is distributed in thefirst embodiment of the information processing system of the invention.First, at step S51, the destination information intervention systemassigns the system identifier of the source information interventionsystem making a connection establishing request for informationdistribution to variable M-from. Next, at step S52, the informationdistributed from the information intervention system having the systemidentifier stored in the variable M-from is assigned to variable InfoX.At step S53, the information distribution section 12 stores theinformation assigned to the variable InfoX in the information holdingsection 11. The information distribution process in the destinationinformation intervention system is now complete.

FIG. 7 is an illustration of an example of the information distributionoperation in the first embodiment of the information processing systemof the invention. An example of the operation shown in FIGS. 5 and 6will be discussed based on a specific example. Here, distribution ofinformation having information identifier id-X from informationintervention system A to information intervention system B will bediscussed. At this time, the source information intervention system isthe information intervention system A and the destination informationintervention system is the information intervention system B. Let thesystem identifiers of the information intervention systems A and B beid-A and id-B respectively. In the example shown in FIG. 7, assume thatthe information holding section 11 of the information interventionsystem A stores information having information identifier id-X andinformation having information identifier id-Y.

First, processing in the source information intervention system A willbe discussed with reference to FIGS. 5 and 7. In the example, theinformation intervention system A is going to distribute the informationhaving the information identifier id-X to the information interventionsystem B, thus at step S41, it assigns the system identifier id-B of thedestination information intervention system B to the variable M-to andthe information identifier id-X of the information to be distributed tothe variable X. Next, at step S42, the information distribution section12 of the information intervention system A searches the network for theinformation intervention system B having the system identifier id-B andestablishes a connection to the information distribution section 12 ofthe information intervention system B. At step S43, the informationdistribution section 12 of the information intervention system A readsthe information having the information identifier id-X from theinformation holding section 11 and assigns the information to thevariable InfoX. Further, at step S44, it distributes the informationassigned to the variable InfoX to the information distribution section12 of the information intervention system B. At step S45, thedistribution sensing section 14 of the information intervention system Asenses the distribution process and records a set of

    (information identifier id-X, destination system identifier id-B, Time)

in the distribution history holding section 15 of the informationintervention system A. In FIG. 7, this record is represented as

    sent id-X to id-B at T1

where T1 is the distribution time of day. The record denotes that theinformation having the information identifier id-X was sent to theinformation intervention system having the information identifier id-Bat the time T1. Thus, the information intervention system A distributesthe information and records the distribution history in the distributionhistory holding section 15.

Next, processing in the destination information intervention system Bwill be discussed with reference to FIGS. 6 and 7. First, at step S51,upon reception of the connection establishing request from theinformation intervention system A at step S42 in FIG. 5, the informationintervention system B establishes a connection and assigns the systemidentifier id-A of the source information intervention system A to thevariable M-from. Next, at step S52, the information distribution section12 of the information intervention system B receives the informationhaving the information identifier id-X distributed from the informationdistribution section 12 of the information intervention system A at stepS44 in FIG. 5, and assigns the information to the variable InfoX. Atstep S53, the information distribution section 12 of the informationintervention system B stores the information assigned to the variableInfoX in the information holding section 11 of the informationintervention system B. The process in which the information interventionsystem A distributes the information to the information interventionsystem B is now complete.

FIG. 8 is an illustration of an example of distribution histories heldin the distribution history holding section in the first embodiment ofthe information processing system of the invention. In FIG. 7, thedistribution history is, for example, shown as

    sent id-X to id-B at T1

The actual contents recorded in the distribution history holding section15 may be thus recorded as a character string, but can also be recordedas binary data. FIG. 8 shows representation of a distribution history asbinary data. The target information identifier corresponds to "id-X,"the destination system identifier to "id-B," and the reception time to"T1."

One row in FIG. 8 represents one distribution history. For example, theinformation on the top row means that information having informationidentifier "1679840-176", was sent to information intervention systemhaving identifier "800287" at 12 hours 9 minutes 4 seconds 41 on Mar.10, 1995. Each time one information is distributed, such a distributionhistory will be added to the distribution history holding section 15. Inthe description to follow, basically the representation

    sent id-X to id-B at Ti

is used for the history contents.

FIG. 9 is an illustration of an example after information distributionin the first embodiment of the information processing system of theinvention. As described above, the information having the informationidentifier id-X was distributed from the information intervention systemA to the information intervention system B. After this, if theinformation flows, for example, as shown in FIG. 4, it is furthermoredistributed from the information intervention system B to theinformation intervention systems C and D. FIG. 9 shows the distributionhistory holding sections 15 of the information intervention systems A-Dafter the information is distributed as shown in FIG. 4. Here, thesystem identifiers of the information intervention systems C and D areid-C and id-D respectively. FIG. 9 shows only a part of theconfiguration in each information intervention system.

As in the information distribution process from the informationintervention system A to the information intervention system B, theinformation is distributed from the information intervention system B tothe information intervention system C. Resultantly, the distributionhistory

    sent id-X to id-C at T2

is recorded in the distribution history holding section 15 of theinformation intervention system B. Likewise, the information isdistributed from the information intervention system B to theinformation intervention system D and resultantly, the distributionhistory

    sent id-X to id-D at T3

is recorded in the distribution history holding section 15 of theinformation intervention system B. Thus, each time information isdistributed, its distribution history is recorded in the distributionhistory holding section 15 of the source information interventionsystem.

Next, information tracing processing will be discussed. FIG. 10 is aflowchart to show an example of processing of the history collectionsection when information is traced in an information intervention systemwhich starts information tracing processing in the first embodiment ofthe information processing system of the invention. Now, when aninformation transfer and distribution route tracing instruction is givenin one information intervention system, first at step S61 the historycollection section 16 gets the system identifier of the home informationintervention system which starts tracing from the system label section13 and assigns the system identifier to variable M-first. It alsoassigns the information identifier of the information to be traced tovariable X. Further, it generates id for distinguishing this tracingfrom another tracing and assigns it to variable Q-id, which is used toidentify tracing instructions to avoid an instruction loop when theinformation intervention systems communicate with each other. If thereis no loop possibility or an alternative method can be used, thevariable Q-id need not be used.

Next, at step S62, the history collection section 16 reads thedistribution histories related to the information identifier assigned tothe variable X from the distribution history holding section 15 andassigns the distribution history to variable History. At S63, whether ornot the variable History is null is checked. If it is null, control goesto step S68; if not null, control goes to step S64.

At step S64, one history information entry is fetched from the variableHistory and is assigned to variable H1. As described above, the historyinformation contains sets of (information identifier, destination systemidentifier, distribution time) and such a set is also assigned to thevariable H1. At step S65, from the variable H1, the destination systemidentifier is fetched and assigned to variable M-to and the distributiontime is fetched and assigned to variable Time. At step S66, the historycollection section 16 instructs the history collection section 16 of theinformation intervention system indicated by the system identifierassigned to the variable M-to to perform process TRACE and notifyM-first. The process TRACE is a process shown in flowcharts in FIGS. 12and 13 discussed later. It is executed in other information interventionsystems than the information intervention system starting the tracing.Since the home system identifier is assigned to the variable M-first,the instruction requests the process TRACE execution result to bereturned to the home information intervention system. At step S67, thehistory collection section 16 stores (variable M-first, variable H1)pair in the collected history holding section 17 and moves thedistribution history recorded in the home distribution history holdingsection 15 to the collected history holding section 17. Then, controlreturns to step S63.

If the variable History is null at step S63, the tracing instructionprocess of the history collection section 16 in the informationintervention system starting the tracing is terminated; after this, thehistory collection section 16 stores tracing reports sent from othersystems in the collected history holding section 17 one after another atstep S68.

FIG. 11 is a flowchart to show an example of processing of the tracinganalysis section when information is traced in the informationintervention system which starts information tracing processing in thefirst embodiment of the information processing system of the invention.The tracing analysis section 18 operates subsequently to the processingof the history collection section 16. Here, processing after all reportsfor the instruction issued by the history collection section 16 to anyother information intervention system are returned will be discussed.

First, at step S71, the tracing analysis section 18 assigns theinformation identifier of the information to be traced to variable X.Next, at step S72, it reads the history information related to theinformation identifier assigned to the variable X from the collectedhistory holding section 17, and assigns the history information tovariable History2. At step S73, whether or not the variable History2 isnull is checked. If it is null, control goes to step S79; if not null,control goes to step S74.

At step S74, nodes corresponding to the system identifiers of the sourcesystems of all history information contained in the variable History2are prepared. At step S75, whether or not the variable History2 is nullis checked. If it is null, control goes to step S79; if not null,control goes to step S76. At step S76, one history information entry isfetched from the variable History2 and is assigned to variable H2. Atstep S77, the source system identifier, destination system identifier,and time in the variable H2 are assigned to variables M-from, M-to, andTime respectively. At step S78, an arc from the node of variable M-fromto the node of variable M-to is prepared. Then, control returns to stepS75.

If the variable History2 is null at step S73 or S75, a prepared tracingroute chart is displayed on the tracing result display section 19 atstep S79.

FIGS. 12 and 13 are a flowchart to show an example of processing of thehistory collection section when information is traced in any otherinformation intervention system than the information intervention systemwhich starts information tracing processing in the first embodiment ofthe information processing system of the invention. This processing isthe TRACE process whose execution instruction is given by theinformation intervention system starting the tracing at step S66 in theflowchart shown in FIG. 10. A TRACE process execution instruction isgiven to another information intervention system from within the TRACEprocess.

Upon reception of a tracing instruction from a different informationintervention system, first at step S81, the history collection section16 assigns initial values to variables as follows: The system identifierof the information intervention system starting the tracing to variableM-first, the system identifier of the information intervention systemgiving the tracing instruction to variable M-from, the system identifierof the home information intervention system to variable M-me, theinformation identifier of the information to be traced to variable X, idof the tracing instruction to variable Q-id, and null to variableResult. At step S82, if the same id as the id assigned to the variableQ-id exists in the collected history holding section 17, the instructionloops, thus the process is terminated. At step S83, the historycollection section 16 reads the distribution histories related to theinformation identifier assigned to the variable X from the distributionhistory holding section 15 and assigns the distribution history tovariable History. At S84, whether or not the variable History is null ischecked. If it is null, control goes to step S90; if not null, controlgoes to step S85.

At step S85, one history information entry is fetched from the variableHistory and is assigned to variable H1. At step S86, the destinationsystem identifier in the variable H1 is assigned to variable M-to andthe time in the variable H1 is assigned to variable Time. At step S87,the information intervention system indicated by the system identifierassigned to the variable M-to is instructed to perform process TRACE andnotify M-first. This instruction requests the history collection section16 of the destination information intervention system to execute processTRACE and return the result to the information intervention systemstarting the tracing. At step S88, (variable M-me, variable H1) pair isadded to the variable Result, whereby the distribution history recordedin the distribution history holding section 15 is added as theinformation to be returned to the information intervention systemstarting the tracing. At step S89, whether or not the variable Historyis null is checked. If it is null, goes to step S91; if not null,control returns to step S85.

If the variable History is null at step S84, it indicates that theinformation is not distributed to any information intervention systemsfollowing the information intervention system. In this case, at stepS90, (variable M-me, null) pair is transmitted to the variable M-firstof the information intervention system giving the TRACE processexecution instruction.

If the variable History is null at step S89, namely, processing for thehistory information stored in the variable History is complete at steps85-88, a home system identifier and history information pair list isstored in the variable Result. At step S91, the contents of the variableResult of the TRACE process execution result are transmitted to theinformation intervention system starting the tracing assigned to thevariable M-first.

To indicate completion of processing for the tracing instruction at stepS92 following steps S90 and S91, the id of the tracing instructionassigned to the variable Q-id is stored in the collected history holdingsection 17. The process TRACE of the history collection section 16 inany other information intervention system than the informationintervention system starting information tracing processing is nowcomplete.

The information tracing processing described above will be discussedwith the specific example shown in FIG. 9. As previously discussed, FIG.9 shows the contents of the distribution history holding sections 15 ofthe information intervention systems after distribution of theinformation having the information identifier id-X from the informationintervention system A to the information intervention system B and fromthe information intervention system B to the information interventionsystems C and D. In the example, assume that an instruction is given fortracing the information having the information identifier id-X from theinformation intervention system A. In this case, the history collectionsection 16 of the information intervention system A performs theprocessing shown in FIG. 10 described above, the tracing analysissection 18 of the information intervention system A performs theprocessing shown in FIG. 11 described above, and the tracing analysissections 16 of the information intervention systems B, C, and D performthe processing shown in FIG. 12 described above.

The transfer and distribution route tracing processing flow of theinformation having the information identifier id-X from the informationintervention system A is as follows: First, the processing of thehistory collection section 16 in the information intervention system Astarting the tracing will be discussed with reference to FIGS. 9 and 10.

When an instruction for tracing the transfer and distribution route ofthe information having the information identifier id-X is issued in theinformation intervention system A, first at step S61, the historycollection section 16 of the information intervention system A assignsthe system identifier id-A of the home information intervention systemstarting the tracing to the variable M-first and the informationidentifier of the information to be traced, id-X, to the variable X.Here, assuming that id "A0001" is prepared, the id of the tracinginstruction is assigned to the variable Q-id.

At step S62, the history collection section 16 of the informationintervention system A reads the distribution histories related to theinformation identifier id-X assigned to the variable X from thedistribution histories stored in the distribution history collectionsection 15. In the example, only one distribution history related to theinformation identifier id-X

    sent id-X to id-B at T1

is found. This distribution history is assigned to the variable History.At step S63, whether or not the variable History is null is checked.Since it is not null, control goes to step S64.

At step S64, one history information entry is fetched from the variableHistory. In the example, the distribution history

    sent id-X to id-B at T1

is fetched and assigned to the variable H1. This distribution historyindicates that the information having the information identifier id-Xwas distributed to the information intervention system having the systemidentifier id-B at the time T1. The variable History from which thehistory information is fetched becomes null. At step S65, from thevariable H1, the destination system identifier id-B is assigned to thevariable M-to and the time T1 is assigned to the variable Time.

At step S66, the history collection section 16 of the informationintervention system A instructs the history collection section 16 of theinformation intervention system having the system identifier id-B,namely, the information intervention system B to perform process TRACEand notify M-first. Since the system identifier id-A of the informationintervention system A is stored in the variable M-first, the instructionrequests the history collection section 16 of the informationintervention system B to trace the transfer and distribution route ofthe information having the information identifier id-X following theinformation intervention system B and return a report of the tracingresult to the information intervention system A.

At step S67, the history collection section 16 of the informationintervention system A stores the following (variable M-first, variableH1) pair:

    (id-A, sent id-X to id-B at time Ti)

in the collected history holding section 17. Then, control returns tostep S63.

When control returns to step S63, the variable History is null, thus thecondition at step S63 "variable History=null" is true. Then, controlgoes to step S68 at which the history collection section 16 of theinformation intervention system A stores the reports concerning thetracing sent from the information intervention system B in the collectedhistory holding section 17 one after another.

Next, the processing of the history collection sections 16 in otherinformation intervention systems than the information interventionsystem A starting the tracing will be discussed with reference to FIGS.9 and 12. At step S66, the history collection section 16 of theinformation intervention system A instructed the history collectionsection 16 of the information intervention system B to perform theprocess TRACE and notify M-first. The history collection section 16 ofthe information intervention system B executes the process TRACE shownin FIG. 12 in response to the instruction.

The history collection section 16 of the information intervention systemB, which receives the tracing instruction from the history collectionsection 16 of the information intervention system A, initializes thevariables at step S81 as follows: The system identifier of theinformation intervention system A starting the tracing, id-A, isassigned to the variable M-first and the system identifier of theinformation intervention system A giving the tracing instruction, id-A,is assigned to the variable M-from. In this example, the tracingstarting system and the instruction giving system happen to be the same;generally, different values are assigned to the variables. Further, thesystem identifier of the home information intervention system B, id-B,is assigned to the variable M-me, the information identifier of theinformation to be traced, id-X, to the variable X, the id of the tracinginstruction, "A0001," to the variable Q-id, and null to the variableResult.

At step S82, whether or not the same id as the id "A0001" of the tracinginstruction assigned to the variable Q-id exists in the collectedhistory holding section 17 is determined. In the example, the sametracing instruction id does not exist in the collected history holdingsection 17 and control goes to the following step.

At step S83, the history collection section 16 of the informationintervention system B reads the distribution histories related to theinformation identifier id-X from the distribution history holdingsection 15. As shown in FIG. 9, two distribution histories related tothe information identifier id-X are stored in the distribution historyholding section 15 of the information intervention system B. The historycollection section 16 reads the two distribution histories and assignsthem to the variable History. Now, the following distribution historiesare stored in the variable History:

    sent id-X to id-C at T2

    sent id-X to id-D at T3

At S84, whether or not the variable History is null is checked. Since itis not null, control goes to step S85 at which one distribution historyis fetched from the variable History and is assigned to the variable H1.Here, assume that

    sent id-X to id-C at T2

is fetched and assigned to the variable H1. The fetched distributionhistory is deleted from the variable History. At step S86, thedestination system identifier id-C in the variable H1 is assigned to thevariable M-to and T2 is assigned to the variable Time.

At step S87, the history collection section 16 of the informationintervention system B instructs the history collection section 16 of theinformation intervention system having the destination system identifierid-C assigned to the variable M-to, namely, the information interventionsystem C to perform process TRACE and notify M-first. Since the systemidentifier id-A of the information intervention system A is stored inthe variable M-first, the instruction requests the history collectionsection 16 of the information intervention system C to trace thetransfer and distribution route of the information having theinformation identifier id-X following the information interventionsystem C and return a report of the tracing result to the informationintervention system A.

At step S88, the (variable M-me, variable H1) pair, namely, (id-B, (sentid-X to id-C at T2)) is added to the variable Result. At step S89,whether or not the variable History is null is checked. In this case, itis not null, and control returns to step S85.

At step S85, one distribution history is fetched from the variableHistory and is assigned to the variable H1. Here,

    sent id-X to id-D at T3

is fetched and assigned to the variable H1. The variable History becomesnull. At step S86, the destination system identifier id-D in thevariable H1 is assigned to the variable M-to and T3 is assigned to thevariable Time.

At step S87, the history collection section 16 of the informationintervention system B instructs the history collection section 16 of theinformation intervention system D to perform process TRACE and notifyM-first. That is, the instruction requests the history collectionsection 16 of the information intervention system D to trace thetransfer and distribution route of the information having theinformation identifier id-X following the information interventionsystem D and return a report of the tracing result to the informationintervention system A.

At step S88, the pair

    (id-B, (sent id-X to id-D at T3))

is added to the variable Result. At step S89, whether or not thevariable History is null is checked. In this case, processing for alldistribution histories in the variable History is complete and thevariable History is null, thus control goes to step S91.

When control goes to step S91, the two information entries

    (id-B, (sent id-X to id-C at T2)); and

    (id-B, (sent id-X to id-D at T3))

are stored in the variable History. At step S91, the information istransmitted to the information intervention system having the systemidentifier id-A stored in the variable M-first, namely, the informationintervention system A.

Last, to indicate completion of processing for the tracing instructionat step S92, the id "A0001" of the tracing instruction is stored in thecollected history holding section 17. The process TRACE in the historycollection section in the information intervention system B is nowcomplete. In the example, after all, steps S85-S88 are repeated twiceand the history collection section 16 of the information interventionsystem B instructs the history collection sections 16 of the informationintervention systems C and D to trace the transfer and distributionroute of the information having the information identifier id-X andreturn a report of the tracing result to the information interventionsystem A, and transmits the information

    id-B: sent id-X to id-C at T2

    id-B: sent id-X to id-D at T3

to the information intervention system A, then completes the process.

At step S87, the history collection section 16 of the informationintervention system B instructed the history collection sections 16 ofthe information intervention systems C and D to perform the processTRACE and notify the information intervention system A. The historycollection sections 16 of the information intervention systems C and Dexecute the process TRACE shown in FIG. 12 in response to theinstruction as the history collection section 16 of the informationintervention system B does.

The history collection section 16 of the information intervention systemC performs initialization at step S81 and checks the tracing instructionid at step S82, then attempts to read the distribution histories relatedto the information identifier id-X from the distribution history holdingsection 15 at step S83, but does not find any. Thus, the variableHistory becomes null. The determination at step S84 becomes true andcontrol goes to step S90 at which the history collection section 16transmits a pair of (M-me, null), for example,

    id-C: null

to the information intervention system A, then completes the process.

Like the history collection section 16 of the information interventionsystem C, the history collection section 16 of the informationintervention system D executes similar steps and transmits

    id-D: null

to the information intervention system A, then completes the process.

Finally, from the information intervention systems B, C, and D, thefollowing information

    id-B: sent id-X to id-C at T2

    id-B: sent id-X to id-D at T3

    id-C: null

    id-D: null

is sent to the information intervention system A.

FIG. 14 is an illustration of an example of the contents of thecollected history holding section in the first embodiment of theinformation processing system of the invention. The history informationcollected in the collected history holding section 17 of the informationintervention system A as described above may be recorded as characterstrings as shown above, but can also be recorded as binary data as shownin FIG. 8, for example. FIG. 14 shows representation of historyinformation collected in the collected history holding section 17 asbinary data. A field for storing the system identifier of the collectionsource (distribution source) information intervention system is providedin addition to the fields of the distribution history shown in FIG. 8.

For example, the information on the second top row in FIG. 14 is adistribution history collected from the information intervention systemwhose system identifier is "800287" and indicates that the informationwhose information identifier is "679840-176" was distributed from theinformation intervention system whose system identifier is "800287" tothe information intervention system whose system identifier is "028765"at the time "1995031322233489." In the example, the system identifier"800287" is id-B, the system identifier "028765" is id-C, theinformation identifier "679840-176" is id-X, and the time"1995031322233489" is T2. That is, the information indicates

    id-B: sent id-X to id-C at T2

This means that it is a history collected from the informationintervention system whose system identifier is id-B and denotes that theinformation whose information identifier is id-X was distributed fromthe information intervention system whose system identifier is id-B tothe information intervention system whose system identifier is id-C atthe time T2.

When the history collection section 16 of the information interventionsystem A executed the processing shown in FIG. 10, it stored thedistribution history fetched from the home distribution history holdingsection 15 in the home collected history holding section 17 as thehistory information on the top row in FIG. 14.

Next, the processing of the tracing analysis section 18 in theinformation intervention system A starting the tracing will be discussedwith reference to FIGS. 9 and 11. The tracing analysis section 18operates subsequently to the processing of the history collectionsection 16. Here, processing after reports for the instruction issued bythe history collection section 16 to the information intervention systemB are returned will be discussed. The collected history holding section17 of the information intervention system A stores the historyinformation sent from the information intervention systems B, C, and Das described above.

First, at step S71, the tracing analysis section 18 in the informationintervention system A assigns the information identifier of theinformation to be traced, id-X, to the variable X. Next, at step S72, itreads the history information related to the information identifier id-Xfrom the collected history holding section 17, and assigns the historyinformation to the variable History2. The following five historyinformation entries are assigned to the variable History2:

    id-A: sent id-X to id-B at T1

    id-B: sent id-X to id-C at T2

    id-B: sent id-X to id-D at T3

    id-C: null

    id-D: null

At step S73, whether or not the variable History2 is null is checked.Since it is not null, control goes to step S74 at which four nodescorresponding to the source system identifiers id-A, id-B, id-C, andid-D of all history information contained in the variable History2 areprepared.

At step S75, whether or not the variable History2 is null is checked. Atthis point in time, it is not null, and control goes to step S76 atwhich one history information entry is fetched from the variableHistory2 and is assigned to the variable H2. Here, assume that

    id-A: sent id-X to id-B at T1

is fetched. It is assigned to the variable H2. At step S77, the sourcesystem identifier id-A, the destination system identifier id-B, and thetime T1 in the variable H2 are assigned to the variables M-from, M-to,and Time respectively. At step S78, an arc from the node M-from to thenode M-to, namely, an arc from the node id-A to the node id-B isprepared. Then, control returns to step S75.

At this point in time, the variable History2 is not yet null. Then, atstep S76, one of the history information entries

    id-B: sent id-X to id-C at T2

is fetched from the variable History2 and is assigned to the variableH2. At steps S77 and S78, an arc from the node id-B to the node id-C isprepared. Likewise, an arc from the node id-B to the node id-D isprepared from the history information entry

    id-B: sent id-X to id-D at T3

For the remaining history information entries

    id-C: null

    id-D: null,

the nodes id-C and id-D are set to the terminating nodes at step S78.

Since the variable History2 is now null, the condition at step S75becomes true and control goes to step S79. When control goes to stepS79, the four nodes for id-A, id-B, id-C, and id-D, the three arcs"id-A→id-B," "id-B→id-C," and "id-B→id-D," and the terminating nodes atid-C and id-D are already prepared, thus the chart thereof is displayedon the tracing result display section 19.

FIG. 15 is an illustration of an example of display of the tracingresult display section in the first embodiment of the informationprocessing system of the invention. The four nodes, the three arcs, andthe two terminating nodes have been prepared as described above, basedon which a graph, for example, as shown in FIG. 15 can be displayed.

In the display example shown in FIG. 15, a QUIT button for closing thewindow, an information name input area, and a RETRIEVE button aredisplayed on the top of the window of the tracing result display section19. The user enters the name of the information whose tracing result isto know in the input field to the right of the INFORMATION NAMEindication. The user can give an information analysis command to thehistory collection section 16 by pressing the RETRIEVE button. Here,assume that the user is to know the distribution route of information Xhaving information identifier id-X and enters information X as theinformation name. After entering the information name, he or she pressesthe RETRIEVE button. Since the RETRIEVE button is a virtual button, theuser can click a mouse button on the position of the RETRIEVE button,for example.

In the example shown in FIG. 15, the nodes prepared as described aboveare indicated by circles and the arcs are indicated by arrows. Thedistribution time of day is displayed near each arrow. The nodeindicating the information intervention system starting the tracingdiffers from other nodes in display method. The node is hatched in FIG.15 for convenience of the illustration; in fact, it can be displayed bychanging the color, brightness, etc. Such graphical distribution routedisplay enables the user to know the information distribution route in avisual form.

Thus, the first embodiment enables the user to trace the transfer anddistribution route and distribution range of information following oneinformation intervention system.

In the description, in the information tracing processing, eachinformation intervention system instructed to check history informationand return a report sends a report directly to the informationintervention system first starting the tracing processing, but theinvention is not limited to the configuration. A report may be sent tothe information intervention system giving the instruction for checkinghistory information and returning a report and be passed in the reverseorder to the information distribution order.

In the description, the history information contains the distributiontime of day in addition to the information identifier and the systemidentifiers. However, to know only the distribution route, etc., thedistribution time of day is not necessarily required and may be omitted.However, to obtain information on the information transfer time or toknow which distribution was first executed, for example, when the sameinformation was distributed or received from more than one informationintervention system, it is convenient to also contain the distributiontime of day in the history information. Of course, other informationpieces may be recorded as history information.

Second Embodiment:

Next, a second embodiment of the information processing system of theinvention will be discussed. The embodiment is configured so thatinformation can be traced as to what transfer and distribution route theinformation was distributed on to one system.

Like the first embodiment, the basic configuration in the secondembodiment is shown in FIG. 1 and therefore the sections will not bediscussed again in detail. The second embodiment differs from the firstembodiment basically in the distribution history contents recorded in adistribution history holding section 15 when information is distributedand in the tracing request direction when information is traced.Specifically, when information is distributed, the system identifier ofthe information destination is recorded in the distribution historyholding section 15 of the source information intervention system in thefirst embodiment; whereas the system identifier of the informationsource is recorded in a distribution history holding section 15 of thedestination information intervention system in the second embodiment.When information is traced, it is traced in the same order as theinformation was distributed in the first embodiment; whereas it istraced in the reverse order to how the information was distributed inthe second embodiment. Such a configuration enables the user to knowwhat route the received information was distributed via, for example.

When information is distributed (received), a distribution sensingsection 14 records the information identifier of the information in thedistribution history holding section 15 together with the systemidentifier of the source information intervention system.

A history collection section 16 reads a distribution history from thedistribution history holding section 15 and based on the distributionhistory, requests the source information intervention system to collectthe distribution histories of the information preceding the sourceinformation intervention system in order and return the distributionhistories to the information intervention system giving the collectioninstruction. Of course, it may request the information interventionsystem to return the distribution histories to the informationintervention system starting the tracing.

Next, the operation in the second embodiment of the informationprocessing system of the invention will be outlined. FIG. 16 is anillustration of an example of an information flow in the secondembodiment of the information processing system of the invention. Itshows four information intervention systems A-D and gives an example inwhich information X is distributed from information intervention systemA to information intervention system B to information interventionsystem C to information intervention system D.

The information intervention system B senses distribution of theinformation X from the information intervention system A and records itsdistribution history in the distribution history holding section 15.Likewise, the information intervention system C (D) also sensesdistribution of the information X from the information interventionsystem B (C) and records its distribution history in the distributionhistory holding section 15.

When an instruction for tracing the distribution route of theinformation X is given in the information intervention system D, thedistribution history of the information X is fetched from thedistribution history holding section 15 of the information interventionsystem D and the information intervention system C from which theinformation X was distributed is instructed to trace the distributionroute of the information X. Here, a method of passing the histories inthe reverse order to how the information was distributed is adopted asthe tracing result reporting method. Upon reception of the instructionfor tracing the distribution route of the information X from theinformation intervention system D, the information intervention system Cfetches the distribution history of the information X from itsdistribution history holding section 15 and instructs the informationintervention system B from which the information X was distributed totrace the distribution route of the information X. Likewise, theinformation intervention system B also fetches the distribution historyof the information X from its distribution history holding section 15and instructs the information intervention system A from which theinformation X was distributed to trace the distribution route of theinformation X. The information intervention system A, which does nothold the distribution history of the information X, does not give anadditional tracing instruction and returns a message to the effect thatthe distribution history related to the information X does not exist tothe information intervention system B. The information interventionsystem B returns the distribution history when the information X wasdistributed from the information intervention system A and a message tothe effect that the distribution history related to the information Xdoes not exist in the information intervention system A to theinformation intervention system C. The information intervention system Creturns the distribution history when the information X was distributedfrom the information intervention system B, the distribution historywhen the information X possessed by the information intervention systemB was distributed from the information intervention system A, and amessage to the effect that the distribution history related to theinformation X does not exist in the information intervention system A tothe information intervention system D, whereby the informationintervention system D can know that the information X was distributed asshown in FIG. 16. Thus, the information distribution route, distributionrange, etc., can be analyzed.

A processing flow as described above will be discussed in detail. First,the information distribution operation will be discussed. FIG. 17 is anillustration of an example of the information distribution operation inthe second embodiment of the information processing system of theinvention. Sections identical with or similar to those previouslydescribed with reference to FIG. 1 are denoted by the same referencenumerals in FIG. 17. Here, a processing flow when information havinginformation identifier id-X is distributed from information interventionsystem A to information intervention system B will be discussed.

As in FIG. 7 in the first embodiment, the information interventionsystem A has the system identifier id-A. An information holding section11 of the information intervention system A stores information havinginformation identifier id-X (information X) and information havinginformation identifier id-Y. The information intervention system B hassystem identifier id-B.

The processing flow when the information intervention system Adistributes information to the information intervention system B is alsothe same as that in the first embodiment except for the distributionhistory entering location and contents. In the first embodiment, theinformation identifier id-X of the distributed information is recordedin the distribution history holding section 15 of the informationintervention system A together with the destination system identifierid-B. In the second embodiment, the information identifier id-X of thedistributed information is recorded in the distribution history holdingsection 15 of the information intervention system B together with thesource system identifier id-A.

Specifically, first an information distribution section 12 of theinformation intervention system A searches the network for theinformation intervention system B based on the system identifier id-Bthereof and establishes a connection to an information distributionsection 12 of the information intervention system B. Next, theinformation distribution section 12 of the information interventionsystem A reads the information X from the information holding section 11and distributes the information to the information distribution section12 of the information intervention system B. Upon reception of theinformation X, the information distribution section 12 of theinformation intervention system B stores the information in theinformation holding section 11.

The distribution sensing section 14 of the information interventionsystem B senses the distribution process, namely, the reception processand records the information identifier id-X of the distributedinformation in the distribution history holding section 15 of theinformation intervention system B together with the source systemidentifier id-A. In the example shown in FIG. 17, the distribution timeT1 is added to the record as

    received id-X from id-A at T1

This record denotes that the information having the informationidentifier id-X was received from the information intervention systemhaving the information identifier id-A at the time T1.

FIG. 18 is an illustration of an example after information distributionin the second embodiment of the information processing system of theinvention. As described above, the information X was distributed fromthe information intervention system A to the information interventionsystem B. If the information flows, for example, as shown in FIG. 16, itis furthermore distributed from the information intervention system B tothe information intervention system C to the information interventionsystem D. FIG. 18 shows the distribution history holding sections 15 ofthe information intervention systems A-D after the information isdistributed as shown in FIG. 16. Here, the system identifiers of theinformation intervention systems C and D are id-C and id-D respectively.FIG. 18 shows only a part of the configuration in each informationintervention system.

As in the information distribution process from the informationintervention system A to the information intervention system B, theinformation is distributed from the information intervention system B tothe information intervention system C. Resultantly, the distributionhistory

    received id-X from id-B at T2

is recorded in the distribution history holding section 15 of theinformation intervention system C. Likewise, the information isdistributed from the information intervention system C to theinformation intervention system D and resultantly, the distributionhistory

    received id-X from id-C at T3

is recorded in the distribution history holding section 15 of theinformation intervention system D. Thus, each time information isdistributed, its distribution history is recorded in the distributionhistory holding section 15 of the source information interventionsystem.

Next, information tracing processing will be discussed with FIG. 18. Inthe description, a method of passing the histories in the reverse orderto how the information was distributed is adopted as the tracing resultreporting method. Of course, the method of returning all reports to theinformation intervention system starting the tracing may be adopted asin the first embodiment.

First, when an information X transfer and distribution route tracinginstruction is given in the information intervention system D, thehistory collection section 16 of the information intervention system Dreads the distribution histories related to the information identifierid-X of the information X from the distribution histories stored in thedistribution history holding section 15. In the example, only onedistribution history

    received id-X from id-C at T3

is found. This distribution history indicates that the information X wasdistributed from the information intervention system C having the systemidentifier id-C at the time T3. Then, the history collection section 16of the information intervention system D requests the history collectionsection 16 of the information intervention system C to trace thetransfer and distribution route of the information X and report thetracing result to the information intervention system D. In addition, itstores a pair of the distribution history and the system identifier id-Dof the information intervention system D, namely, the following historyinformation

    id-D: received id-X from id-C at time T3

in a collected history holding section 17 of the informationintervention system D.

The history collection section 16 of the information intervention systemC, which receives the request from the information intervention systemD, reads the distribution histories related to the informationidentifier id-X of the information X from the distribution historiesstored in the distribution history holding section 15. In the example,the following distribution history

    received id-X from id-B at T2

is found. The history collection section 16 of the informationintervention system C stores a pair of the distribution history and thehome system identifier id-C, namely, the following history information

    id-C: received id-X from id-B at time T2

in a collected history holding section 17 of the informationintervention system C. Further, the distribution history indicates thatthe information X was distributed from the information interventionsystem B having the system identifier id-B at the time T2. Then, thehistory collection section 16 of the information intervention system Crequests the information intervention system B to trace the transfer anddistribution route of the information X and report the tracing result tothe information intervention system C.

Likewise, the history collection section 16 of the informationintervention system B reads the distribution histories related to theinformation identifier id-X of the information X from the distributionhistory holding section 15 and stores the following history information

    id-B: received id-X from id-A at time T1

in a collected history holding section 17 of the informationintervention system B and requests the information intervention system Ato trace the transfer and distribution route of the information X andreport the tracing result to the information intervention system B.

Likewise, the history collection section 16 of the informationintervention system A attempts to read the distribution historiesrelated to the information identifier id-X of the information X from thedistribution history holding section 15, but the distribution historyholding section 15 of the information intervention system A does notstore any distribution history related to the information identifierid-X of the information X. Thus, the history collection section 16 ofthe information intervention system A reports the following information

    id-A: null

to the information intervention system B.

The history collection section 16 of the information intervention systemB, which receives the report from the history collection section 16 ofthe information intervention system A, fetches the history information

    id-B: received id-X from id-A at time T1

from the collected history holding section 17, adds it to the historyinformation received from the information intervention system A, andreports the information to the information intervention system C.

Likewise, the history collection section 16 of the informationintervention system C, which receives the report from the historycollection section 16 of the information intervention system B, fetchesthe history information from the collected history holding section 17,adds it to the history information received from the informationintervention system B, and reports the information to the informationintervention system D.

The history collection section 16 of the information intervention systemD, which receives the report from the history collection section 16 ofthe information intervention system C, stores the received historyinformation in the collected history holding section 17 of theinformation intervention system D. Finally, the following historyinformation

    id-A: null

    id-B: received id-X from id-A at time T1

    id-C: received id-X from id-B at time T2

    id-D: received id-X from id-C at time T3

is stored in the collected history holding section 17 of the informationintervention system D.

A tracing analysis section 18 of the information intervention system Danalyzes the history information and determines that the information Xwas distributed from the information intervention system A to theinformation intervention system B to the information intervention systemC to the information intervention system D. It displays the analysisresult on a tracing result display section 19.

FIG. 19 is an illustration of an example of display of the tracingresult display section in the second embodiment of the informationprocessing system of the invention. The display form in FIG. 19 issimilar to that in FIG. 15. According to the history informationcollected in the collected history holding section 17 of the informationintervention system D as described above, the existing informationintervention systems A, B, C, and D are indicated by circles as nodesand the three arcs "id-A→id-B," "id-B→id-C," and "id-C→id-D" areprepared and indicated by arrows. The distribution time of day isdisplayed near each arrow. In the display example shown in FIG. 19, thenode indicating the information intervention system D starting thetracing differs from other nodes in display way.

Third Embodiment:

Next, a third embodiment of the information processing system of theinvention will be discussed. The embodiment enables tracing of alltransfer and distribution routes and all distribution ranges ofinformation. Basically, it is provided by combining the first and secondembodiments, wherein information can be traced in the same order as andthe reverse order to how it was distributed from one informationintervention system, and all transfer and distribution routes and alldistribution ranges of information can be traced. The second embodimentis the same as the first embodiment in basic configuration, shown inFIG. 1 and therefore the sections will not be discussed again in detail.

When receiving information distribution from any other informationintervention system, a distribution sensing section 14 records theinformation identifier of the information in a distribution historyholding section 15 together with the system identifier of the sourceinformation intervention system. When distributing information to anyother information intervention system, it records the informationidentifier of the information in the distribution history holdingsection 15 together with the system identifier of the destinationinformation intervention system.

A history collection section 16 reads distribution histories from thedistribution history holding section 15 and based on the readdistribution histories, requests the destination and source informationintervention systems to collect the distribution histories of theinformation preceding and following the information intervention systemsin order and return the distribution histories to the informationintervention system starting the tracing. Of course, it may request theinformation intervention systems to return the distribution histories tothe information intervention system receiving the tracing instruction.

Next, the operation in the third embodiment of the informationprocessing system of the invention will be outlined. FIG. 20 is anillustration of an example of an information flow in the thirdembodiment of the information processing system of the invention. Itshows six information intervention systems A-F and gives an example inwhich information X is distributed from information intervention systemA to information intervention systems B and F, from informationintervention system B to information intervention systems C and D, frominformation intervention system C to information intervention system D,and from information intervention system D to information interventionsystem E.

The information intervention system A records distribution histories ofdistribution of the information X to the information interventionsystems B and F in the distribution history holding section 15. Theinformation intervention system B records distribution histories ofdistribution of the information X from the information interventionsystem A and distribution of the information X to the informationintervention systems C and D in the distribution history holding section15. Likewise, the information intervention system C records distributionhistories of distribution of the information X from the informationintervention system B and distribution of the information X to theinformation intervention system D in the distribution history holdingsection 15; the information intervention system D records distributionhistories of distribution of the information X from the informationintervention systems B and C and distribution of the information X tothe information intervention system E in the distribution historyholding section 15; the information intervention system E records adistribution history of distribution of the information X from theinformation intervention system D in the distribution history holdingsection 15; and the information intervention system F records adistribution history of distribution of the information X from theinformation intervention system A in the distribution history holdingsection 15.

When an instruction for tracing the distribution route of theinformation X is given in the information intervention system B, thedistribution histories of the information X are fetched from thedistribution history holding section 15 of the information interventionsystem B. In this case, since the distribution histories of distributionof the information X from the information intervention system A anddistribution of the information X to the information interventionsystems C and D are recorded, the information intervention system Binstructs the information intervention systems to trace the distributionroutes of the information X. It can know all distribution routes anddistribution ranges of the information as shown in FIG. 20 by carryingout an analysis on the history information collected from theinformation intervention systems. Thus, the third embodiment enables theuser to trace all distribution routes of information from anyinformation intervention system to which analysis information wasdistributed.

A processing flow as described above will be discussed in detail. First,the information distribution operation will be discussed. Informationdistribution processing is a combination of the processing shown in thefirst embodiment and that in the second embodiment. Distribution of theinformation X from the information intervention system A to theinformation intervention system B is considered. In this case, as shownin FIG. 7, the distribution history

    sent id-X to id-B at T1

is recorded in the distribution history holding section 15 of the sourceinformation intervention system A. As shown in FIG. 17, the distributionhistory

    received id-X from id-A

is recorded in the distribution history holding section 15 of thedestination information intervention system B. At this time, thedistribution time of day may be recorded in either of them; in theexample, it is recorded only in the distribution history recorded in thesource information intervention system. It can also be recorded only inthe distribution history recorded in the destination informationintervention system or in the distribution histories recorded in boththe source and destination information intervention systems.

FIG. 21 is an illustration of an example after information distributionin the third embodiment of the information processing system of theinvention. As described above, the information X was distributed fromthe information intervention system A to the information interventionsystem B. If the information flows, for example, as shown in FIG. 20,further the distribution history

    sent id-X to id-F at T6

indicating that the information X was distributed to the informationintervention system F is recorded in the distribution history holdingsection 15 of tie information intervention system A. When theinformation X was distributed to the information intervention system F,the distribution history

    received id-X from id-A

is recorded in the distribution history holding section 15 of theinformation intervention system F.

Further, the distribution histories

    sent id-X to id-C at T2

    sent id-X to id-D at T3

indicating that the information X was distributed to the informationintervention systems C and D are recorded in the distribution historyholding section 15 of the information intervention system B. When theinformation X was distributed to the information intervention systems Cand D, the distribution history

    received id-X from id-B

is recorded in the distribution history holding sections 15 of theinformation intervention systems C and D. Since the informationintervention system C further distributes the information X to theinformation intervention-system D, further the distribution history

    sent id-X to id-D at T4

is recorded in the distribution history holding section 15 of theinformation intervention system C. In response to this, the distributionhistory

    received id-X from id-C

is recorded in the distribution history holding section 15 of theinformation intervention system D. Since the information interventionsystem D distributes the information X to the information interventionsystem E, further the distribution history

    sent id-X to id-E at T5

is recorded in the distribution history holding section 15 of theinformation intervention system D. In response to this, the distributionhistory

    received id-X from id-D

is recorded in the distribution history holding section 15 of theinformation intervention system E. When distribution of the informationX as shown in FIG. 20 was thus executed, the distribution histories asshown in FIG. 21 are recorded in the distribution history holdingsections 15 of the information intervention systems A-F.

Next, transfer and distribution route tracing processing of theinformation X from the information intervention system B will bediscussed with the example shown in FIG. 21. In the description thatfollows, assume that an information X transfer and distribution routetracing instruction is given in the information intervention system B.

When an information X transfer and distribution route tracinginstruction is given in the information intervention system B, thehistory collection section 16 of the information intervention system Breads the distribution histories related to the information identifierid-X of the information X from the distribution histories stored in thedistribution history holding section 15. In the example, the followingthree distribution histories

    received id-X from id-A

    sent id-X to id-C at T2

    sent id-X to id-D at T3

are found.

These found distribution histories indicate that the informationintervention system B received the information X from the informationintervention system A and distributed it to the information interventionsystems C and D at the times T2 and T3. The information interventionsystem B requests the information intervention systems A, C, and D totrace the transfer and distribution routes of the information Xpreceding and following the systems A, C, and D and report the tracingresult to the information intervention system B. In addition, it storespairs of each of the distribution histories and the system identifierid-B of the information intervention system B in the collected historyholding section 17.

Each of the information intervention systems A, C, and D, which receivesthe request from the information intervention system B, reads thedistribution histories related to the information identifier id-X of theinformation X from the distribution histories stored in the distributionhistory holding section 15. Based on the distribution histories, theinformation intervention systems A, C, and D request their preceding andfollowing information intervention systems to trace the transfer anddistribution routes of the information X and report the tracing resultto the information intervention system B. In addition, each of thesystems A, C, and D returns pairs of each of the read distributionhistories and its own system identifier to the information interventionsystem B.

For example, the information intervention system A fetches thedistribution histories recorded in the distribution history holdingsection 15

    sent id-X to id-B at T1

    sent id-X to id-F at T6

and requests the information intervention systems B and F to trace thetransfer and distribution routes of the information X and report thetracing result to the information intervention system B. In addition, itreturns the history information consisting of the distribution historiesand its system identifier in pairs

    id-A: sent id-X to id-B at T1

    id-A: sent id-X to id-F at T6

to the information intervention system B.

Likewise, the information intervention system F, which receives therequest from the information intervention system A, returns the historyinformation

    id-F: received id-X from id-A

to the information intervention system B. At this time, the informationintervention system F requests the information intervention system totrace the transfer and distribution route of the information X andreport the tracing result to the information intervention system B.However, As described in the flowchart of the information tracingprocessing in the first embodiment of the invention shown in FIG. 10,the tracing instruction id is used to check a process loop, thus theinformation intervention system A does not perform duplicate informationtracing processing, whereby an infinite loop of a request between theinformation intervention systems can be prevented.

Likewise, each of the information intervention systems C, D, and Ereturns pairs of each of the distribution histories recorded in thedistribution history holding section 15 and the system identifier to theinformation intervention system B. The information intervention system Bstores the history information sent from the information interventionsystems in the collected history holding section 17. Finally, thefollowing history information

    id-B: received id-X from id-A

    id-B: sent id-X to id-C at T2

    id-B: sent id-X to id-D at T3

    id-C: received id-X from id-B

    id-C: sent id-X to id-D at time T4

    id-D: received id-X from id-B

    id-D: received id-X from id-C

    id-D: sent id-X to id-E at time T5

    id-E: received id-X from id-D

    id-A: sent id-X to id-B at time T1

    id-A: sent id-X to id-F at time T6

    id-F: received id-X from id-A

is stored in the collected history holding section 17 of the informationintervention system B.

A tracing analysis section 18 of the information intervention system Banalyzes the history information, thereby determining all distributionroutes of the information X and displaying the analysis result on atracing result display section 19. An example analysis method is asfollows:

As the distribution histories are recorded as described above, a historyis recorded in both destination and source systems in one distribution.That is, the history information stored in the collected history holdingsection 17 contains duplicate information indicating the same fact.Thus, it is sufficient to use only either of them for analyzing thedistribution route. For example, only the history information related to"sent" can be selected from the above-mentioned history information foruse. The selected history information is as follows:

    id-B: sent id-X to id-C at T2

    id-B: sent id-X to id-D at T3

    id-C: sent id-X to id-D at time T4

    id-D: sent id-X to id-E at time T5

    id-A: sent id-X to id-B at time T1

    id-A: sent id-X to id-F at time T6

Of course, only the history information related to "received" can beselected for use.

Next, the system identifiers are extracted from the selected historyinformation and nodes are prepared for them. Here, the six nodes id-A,id-B, id-C, id-D, id-E, and id-F can be prepared. Further, the followingarcs are prepared from the history information:

    id-B id-C at T2

    id-B id-D at T3

    id-C id-D at T4

    id-D id-E at T5

    id-A id-B at T1

    id-A id-F at T6

The analysis is now complete and the result is displayed on the tracingresult display section 19.

FIG. 22 is an illustration of an example of display of the tracingresult display section in the third embodiment of the informationprocessing system of the invention. The display form in FIG. 21 issimilar to that in FIG. 15. According to the result of the analysisusing the history information collected in the collected history holdingsection 17 of the information intervention system B as described above,for example, the distribution route of the information X can bedisplayed as shown in FIG. 22. Nodes are indicated by circles and arcsare indicated by arrows. The distribution time of day is displayed neareach arrow. The node indicating the information intervention system Bdiffers from other nodes in display way so that the informationintervention system starting the tracing can be seen.

By seeing such display, the user can grasp the entire distributionroutes and distribution ranges of the information X. The distributiontime display enables the user to know the distribution timing as towhether distribution of the information X from the informationintervention system D to the information intervention system E, forexample, was executed after distribution from the informationintervention system B or C or both systems.

Fourth Embodiment:

Next, a fourth embodiment of the information processing system of theinvention will be discussed. In the embodiment, histories related toinformation prepared or changed by the user are also recorded, wherebyif information is modified in an intermediate point of distribution ofthe information, it can be traced throughout the informationdistribution route containing the modification.

The embodiments we have discussed assume that information is distributedvia a large number of information intervention systems with the originalinformation intact without modification, and the distribution route ofthe information is traced. However, in the fourth embodiment, ifinformation is modified in an intermediate point of distribution of theinformation or new information is prepared based on several informationitems, not only the modified information, but also integration of theoriginal information and the modified information can be traced.

FIG. 23 is block diagrams to show a fourth embodiment of the informationprocessing system of the invention. Sections identical with or similarto those previously described with reference to FIG. 1 are denoted bythe same reference numerals in FIG. 23 and will not be discussed again.In FIG. 23, numeral 21 designates an information processing section;numeral 22, an information identifier management section; and numeral23, an information preparation sensing section. The fourth embodiment issimilar to the first to third embodiments in basic configuration; theinformation identifier management section 22 for giving a newinformation identifier to information when the information is preparedor modified and the information preparation sensing section 23 forsensing information preparation or modification and storing its historyinformation in a distribution history holding section may be added tothe configuration shown in FIG. 1. The information processing section 21is a section for generally processing information and here forpreparing, modifying, etc., information.

When information is prepared or modified, the information identifiermanagement section 22 gives a new information identifier to theinformation, Information identifiers are managed so that they are notduplicate with those given by other information intervention systems. Asan possible information identifier management method, for example, acombination of the system identifier held in each informationintervention system and a serial number given to information prepared orchanged through the information intervention system is used as theinformation identifier of the information. For example, if the systemidentifier is 6892678, it is combined with the serial numbers toinformation prepared or changed on the information intervention systemto produce 6892678-1, 6892678-2, 6892678-3, . . . used as theinformation identifiers, whereby duplication of the identifiers forinformation can be avoided.

The information preparation sensing section 23 monitors the informationprocessing section 12 for sensing information preparation ormodification, and stores its preparation history in a distributionhistory holding section 15. For example, if information whoseinformation identifier is W is prepared at time T1, the followingpreparation history

    created W at T1

is stored in the distribution history holding section 15. If informationwhose information identifier is P is prepared based on information whoseinformation identifier is Q at time T2, the preparation history

    created P from Q at T2

is stored in the distribution history holding section 15.

Next, the operation in the fourth embodiment of the informationprocessing system of the invention will be outlined. FIG. 24 is anillustration of an example of an information flow in the fourthembodiment of the information processing system of the invention,wherein the dotted lines denote a flow of information X, the alternatelong and short dash line denotes a flow of information Y, and the solidline denotes a flow of information Z.

Like FIG. 4, FIG. 24 shows four information intervention systems A-D,wherein information X is prepared in the information intervention systemA and is distributed from the information intervention system A to theinformation intervention system B from which it is distributed to theinformation intervention systems C and D. In the embodiment, after suchdistribution, the information X is modified to prepare information Y inthe information intervention system D and the information Y isdistributed to the information intervention system B. Further, theinformation Y is modified to prepare information Z in the informationintervention system B and the information Z is distributed to theinformation intervention system C.

FIG. 25 is an illustration of an example after information distributionin the fourth embodiment of the information processing system of theinvention. When information distribution as shown in FIG. 24 isexecuted, distribution and preparation histories are recorded in thedistribution history holding sections 15 of the information interventionsystems A-D. At this time, the distribution histories are stored as inthe first embodiment. Of course, they can also be recorded as in thesecond or third embodiment.

First, the information X is prepared in the information interventionsystem A. When the information X is prepared in the informationprocessing section 21, the information identifier management section 22gives information identifier id-X to the prepared information X. Theinformation preparation sensing section 23 senses preparation of theinformation X in the information processing section 21, prepares thepreparation history

    created id-X at T1

from the information identifier id-X of the information X and thepreparation time T1, and records it in the distribution history holdingsection 15. As in the first embodiment, the distribution history of theinformation X

    sent id-X to id-B at T2

is recorded in the distribution history holding section 15 of theinformation intervention system A and the distribution histories of theinformation X

    sent id-X to id-C at T3

    sent id-X to id-D at T4

are recorded in the distribution history holding section 15 of theinformation intervention system B.

Since the information Y is prepared based on the information X in theinformation intervention system D, the preparation history

    created id-Y from id-X at T5

is recorded in the distribution history holding section 15 of theinformation intervention system D and as the information Y isdistributed to the information intervention system B, the distributionhistory of the information Y

    sent id-Y to id-B at T6

is also recorded therein.

Since the information Z is prepared based on the information Y receivedfrom the information intervention system C in the informationintervention system B and is distributed to the information interventionsystem D, further the following preparation and distribution histories

    created id-Z from id-Y at T7

    sent id-Z to id-D at T8

are recorded in the distribution history holding section 15 of theinformation intervention system B.

Finally, as shown in FIG. 25, the preparation and distribution historiesare recorded in the distribution history holding sections 15 of theinformation intervention systems A-D.

Next, transfer and distribution route tracing processing of theinformation X and its modified information from the informationintervention system A will be discussed with the example shown in FIG.25. When a transfer and distribution route tracing instruction of theinformation X and its modified information is given in the informationintervention system A, the information intervention systems performsimilar processing to that shown in the first embodiment.

Only the information X is traced in the first embodiment; in the fourthembodiment, if a preparation history based on the information X exists,subsequently prepared information is also traced.

Specifically, when the information intervention system B instructs theinformation intervention system D to trace the information X, theinformation intervention system D fetches the preparation history

    created id-Y from id-X at T5

from the distribution history holding section 15 and fetches thedistribution history related to the information identifier id-Y, thenstarts tracing the information Y as in the first embodiment. Itinstructs the information intervention system B to trace the informationY. The information intervention system B does not contain thedistribution history of the information Y, but contains the preparationhistory based on the information Y

    created id-Z from id-Y at T7

A history collection section 16 of the information intervention system Bfetches the preparation history from the distribution history holdingsection 15 and based on the preparation history, further fetches thedistribution history related to the information identifier id-Z from thedistribution history holding section 15 and performs tracing processingfor the information Z.

After all, a collected history holding section 17 of the informationintervention system A stores the following history information:

    id-A: created id-X at T1

    id-A: sent id-X to id-B at T2

    id-B: sent id-X to id-C at T3

    id-B: sent id-X to id-D at T4

    id-B: created id-Z from id-Y at T7

    id-B: sent id-Z to id-C at T8

    id-C: null

    id-D: created id-Y from id-X at T5

    id-D: sent id-Y to id-B at T6

FIG. 26 is an illustration of an example of the contents of thecollected history holding section in the fourth embodiment of theinformation processing system of the invention. The history informationcollected in the collected history holding section 17 of the informationintervention system A as described above may be recorded as characterstrings as shown above, but can also be recorded as binary data as shownin FIG. 8, for example. FIG. 26 shows representation of historyinformation collected in the collected history holding section 17 asbinary data. Each history information entry consists of a collectionsource system identifier, operation type, target information identifier,original information identifier, destination system identifier, andtime.

The operation type in the embodiment is provided for distinguishing"send" from "create" and may be a 1-bit flag. When the operation type is"send," information is stored in the target information identifier, thedestination system identifier, and the time. When the operation type is"create," information is stored in the target information identifier,the original information identifier, and the time. If new information isprepared, the original information identifier is made null.

After the history collection, a tracing analysis section 18 of theinformation intervention system A analyzes the collected historyinformation as in the first embodiment. First, four nodes id-A, id-B,id-C, and id-D are prepared based on the system identifiers of theinformation intervention systems A-D. Next, arcs are prepared based onthe history information having "sent" for each information identifier.The following five arcs are prepared:

    id-X: id-A→id-B at T2

    id-X: id-B→id-C at T3

    id-X: id-B→id-D at T4

    id-Z: id-B→id-C at T8

    id-Y: id-D→id-B at T6

Further, information modification histories are prepared based on thehistory information having "created." The following modificationhistories are prepared:

    id-A: null→id-X at T1

    id-B: id-Y→id-Z at T7

    id-D: id-X→id-Y at T5

The analysis is now complete, then the result is displayed on a tracingresult display section 19.

FIG. 27 is an illustration of an example of distribution route displayof a tracing result display section in the fourth embodiment of theinformation processing system of the invention. FIG. 28 is anillustration of an example of preparation process display of the tracingresult display section in the fourth embodiment of the informationprocessing system of the invention. In information distribution routedisplay, the tracing result of only a single information item isdisplayed in the first embodiment; the tracing result display section 19in the fourth embodiment displays trace information and modificationhistories of more than one information item. Therefore, informationitems need to be distinguished from each other. As shown in FIG. 27, theinformation names, such as "X (T2)" and "Y (T6)," are displayed near thearrow lines connecting the information intervention systems, and furtherthe information items are displayed in different line types. This is anexample, and various display methods can be used, for example, differentcolors are used to distinguish the information items. Of course, thetracing result may be displayed separately for each information item asin the first embodiment depending on selection of the user.

As shown in FIG. 28, only information preparation and modificationhistories may be extracted for display. In the display example shown inFIG. 28, the information items are represented as nodes, which arecircled. Information modification based on a preparation history isrepresented as an arc, which is denoted by an arrow. The display exampleshown in FIG. 28 means that the information X was prepared in theinformation intervention system A at the time T1, that the information Ywas prepared based on the information X in the information interventionsystem B at the time T5, and that the information Z was prepared basedon the information Y in the information intervention system D at thetime T7.

The display forms can be switched whenever necessary as commanded by theuser. Any other display form such as a table format may be adopted,needless to say.

In the fourth embodiment, information preparation or modificationhistories are also recorded in addition to information distributionhistories. Further, a detailed information history may be recorded as tohow which part of information is modified. In addition, a historyrelated to use of information may be recorded. For example, such ahistory indicating that information was used by one application may berecorded. In doing so, use of the information by one application can betraced.

Fifth Embodiment:

Next, a fifth embodiment of the information processing system of theinvention will be discussed. In the embodiments we have discussed,information is provided with an information label section in which itsinformation identifier is held. In the fifth embodiment, informationdoes not have an information label section and consists of only aninformation main body, and an information identifier is calculated fromthe information main body as required.

FIG. 29 is a block diagram to show the fifth embodiment of theinformation processing system of the invention. FIG. 30 is anillustration of an example of the format of information in the fifthembodiment of the information processing system of the invention.Sections identical with or similar to those previously described withreference to FIG. 1 are denoted by the same reference numerals in FIG.29 and will not be discussed again. In FIG. 29, numeral 24 designates aninformation identifier calculation section. An information interventionsystem 1 in the fifth embodiment has the information identifiercalculation section 24 in addition to the configuration of the firstembodiment, as shown in FIG. 29. The information identifier calculationsection 24 calculates an information identifier to distinguish oneinformation item from other information items from the information mainbody. On the other hand, information consists of only an informationmain body, as shown in FIG. 30.

In the first embodiment, when information is distributed from one systemto another, the distribution sensing section 14 records the informationidentifier of the information in the distribution history holdingsection 15 of the source information intervention system together withthe destination system identifier of the information. At the time, theinformation identifier held in the information label section of theinformation is used as the information identifier recorded in thedistribution history holding section 15. In contrast, in the fifthembodiment, an information identifier calculated by the informationidentifier calculation section 24 from the information main body is usedas the information identifier recorded in a distribution history holdingsection 15 when information is distributed.

That is, in the first embodiment, one information X has an informationlabel section in which, for example, information identifier id-X ispreviously held. When the information X is distributed from theinformation intervention system A to the information intervention systemB, the distribution sensing section 14 of the information interventionsystem A senses the distribution process and records the informationidentifier id-X of the distributed information X in the distributionhistory holding section 15 of the information intervention system Atogether with the destination system identifier id-B.

In contrast, in the fifth embodiment, information X consists of only theinformation main body thereof and does not hold an informationidentifier such as id-X. For example, when the information X isdistributed from information intervention system A to informationintervention system B, a distribution sensing section 14 of theinformation intervention system A senses the distribution process andrecords the information identifier of the distributed information X inthe distribution history holding section 15 of the informationintervention system A together with the destination system identifierid-B. At this time, the information X does not hold its informationidentifier, but the information identifier calculation section 24 of theinformation intervention system A calculates an information identifierof the information X based on the information main body thereof andrecords the information identifier in the distribution history holdingsection 15. Assuming that the information identifier of the informationX calculated by the information identifier calculation section 24 isid-X', a distribution history is recorded as

    sent id-X' to id-B at T1

in the distribution history holding section 15 of the informationintervention system A as in the first embodiment.

The information identifier calculation section 24 is adapted tocalculate and output the same information identifier for the sameinformation regardless of which information intervention system theinformation identifier calculation section 24 exists in, enabling theinformation X to be handled as if it held the information identifierid-X'.

Such a configuration enables the invention to also be applied toinformation having no information label section. Since information doesnot have an information label section, an event in which the informationcannot be processed because the information main body and informationlabel section are separated does not occur.

The information identifier calculation method in the informationidentifier calculation section 24 may be any if it can calculate, basedon an information main body, an information identifier capable ofdistinguishing one information item from others in an environment towhich the invention is applied. For example, a unidirectional hashfunction often used in cryptographic theories can be used.

The unidirectional hash function is a function for converting a bitstring of any length into a bit string of a certain length, and has afeature of scarcely outputting the same value if different bit stringsare input. It is often used with cryptographic theories, and has afeature of outputting different values if data is compressed to acertain length and input data is different. This feature can be used toidentify information in the embodiment. For example, in OKAMOTO Eiji,"Angou Riron Nyumon (Introduction to Cryptographic Theories)" KyouritsuShuppan Kabushikigaisha, 1993, pp. 138-140, a large number of specificunidirectional hash function examples are proposed. One of them is SHA(secure hash algorithm). According to the book, the SHA, which is astandard proposal of the unidirectional hash function indicated byStandard Bureau of Department of Commerce in the United States (NIS),outputs 160 bits as a hash value for a message (information to betransmitted) of any length (less than 264 bits). As a hash functionexample by the SHA, the book describes SHA output of a messageconsisting of ASCII code of a, b, c

    01100001 01100001 01100011

becomes

    0164B8A9 14CD2A5E 74C4F7FF 082C4D97 F1EDF880

in 32-bit word units.

The SHA, which is described in detail in the book, comprises thefollowing three steps:

(1) Dividing a message by a certain length;

(2) performing operations of exclusive OR, bit shift, etc., incombination for each message division; and

(3) outputting a hash value based on the operation results at step (2)for all message divisions.

By performing such processing, the information identifier calculationsection 24 calculates an information identifier from the informationmain body. The distribution sensing section 14 uses the informationidentifier calculated by the information identifier calculation section24 to prepare a history and records the prepared history in thedistribution history holding section 15. Processing of other componentsis basically similar to that in the first embodiment and will not bediscussed again. The fifth embodiment can also be applied to the secondto fourth embodiments.

Sixth Embodiment:

Next, a sixth embodiment of the information processing system of theinvention will be discussed. The sixth embodiment enables tracing theinformation transfer and distribution route and distribution range inuser units rather than system units.

FIG. 31 is a block diagram to show the sixth embodiment of theinformation processing system of the invention. Sections identical withor similar to those previously described with reference to FIG. 1 aredenoted by the same reference numerals in FIG. 31 and will not bediscussed again. In FIG. 31, numeral 25 designates a user certificationsection. The basic configuration of an information intervention system 1is the same as that in the first embodiment except that it includes theuser certification section 25 in place of the system label section 13 inthe first embodiment.

The user certification section 25 holds the user identifiercorresponding to the user. It certifies the user to be valid in aninteractive mode if he or she is valid. When certification results insuccess, the user certification section 25 enables use of the useridentifier corresponding to the user. The user certification method mayuse a conventional technique with passwords, ID cards, etc., forexample.

The user identifiers need to be managed so that they are not duplicatewith other users in a tracing assumed area. The real format of the useridentifier may be similar to the format of the information or systemidentifier as described so far.

After a user certification process is executed in the user certificationsection, the subsequent information distribution process and tracingprocess are almost the same as those in other embodiments except thatthe user identifiers rather than the system identifiers are used.

FIG. 32 is an illustration of an example of information flows in thesixth embodiment of the information processing system of the invention.It resembles the example of information flows in the first embodimentshown in FIG. 4. In the sixth embodiment, information X is distributedfrom user U1 to user U2 and from user U2 to users U3 and U4.

The processing flow when the user U1 distributes the information X tothe user U2 will be simply discussed in relation to the firstembodiment. A distribution sensing section 14 monitors an informationdistribution section 12 and can sense that the user U1 distributes theinformation X to the user U2. The distribution sensing section 14 of theuser U1 senses the distribution process and records the informationidentifier id-X of the distributed information X in a distributedhistory holding section 15 of the user U1 together with the destinationuser identifier id-U2, for example, as a distribution history like

    sent id-X to id-U2 at T1

This distribution history means that the user U1 with the useridentifier id-U1 distributed the information X with the informationidentifier id-X to the user U2 with the user identifier id-U2 at thetime T1.

Next, an information tracing process flow will be simply discussed. Whena transfer and distribution route tracing instruction of the informationX is given from the user U1, a history collection section 16 of the userU1 reads distribution histories related to the information identifierid-X of the information X from the distribution histories stored in thedistribution history holding section 15. In the example, the historyinformation

    sent id-X to id-U2 at T1

is found. Then, the user U2 with the user identifier id-U2 is requestedto trace the transfer and distribution route of the information X andreport the tracing result to the user U1. In addition, the distributionhistory and the user identifier id-U1 of the user U1 are stored in acollected history holding section 17 in a pair. Such a process isrepeated, whereby the history information based on the users iscollected in the collected history holding section 17. The collectedhistory information is analyzed, whereby information tracing based onthe users can be executed.

FIG. 33 is an illustration of an example of display of a tracing resultdisplay section in the sixth embodiment of the information processingsystem of the invention. In the sixth embodiment, the user identifiersare extracted from the history information collected in the collectedhistory holding section 17, and are used as nodes. Arcs are preparedfrom the history information. Thus, the nodes represent the users ascompared with the display example in the first embodiment shown in FIG.15.

In the sixth embodiment, the information intervention systems areprovided in a one-to-one correspondence with the users. However, anumber of users often share a workstation, etc. In this case, a virtualinformation intervention system for each user may be constructed in theworkstation. Such a virtual information intervention system can also beapplied, for example, when the user uses a number of workstations on anetwork.

The configuration for using the user identifiers shown in the sixthembodiment can be applied not only to the first embodiment, but also tothe second to fifth embodiments.

Seventh Embodiment:

Next, a seventh embodiment of the information processing system of theinvention will be discussed. In the embodiments discussed so far,information exchange connected by networks have mainly been described.However, information distribution is not limited to it. Informationexchange disconnected from a network, for example, informationdistribution via information media disconnected from a network such asfloppy disk may often be executed.

In this case, a problem is a broken link between the source anddestination when information is distributed via information media. Thesource party can write information onto media without determining anydestination and pass to nonspecific destinations. The informationreceiving party (destination) cannot locate the source of theinformation simply by seeing the information.

To solve the problem, either of the following two methods can beadopted:

(1) Information is provided with a distribution history holding sectionfor writing a distribution history consisting of a source systemidentifier and time of day; or

(2) A medium is provided with a distribution history holding section forwriting a distribution history consisting of a source system identifierand time of day.

These two methods differ only in distribution history holding location.

First, the method of providing information with a distribution historyholding section for writing a distribution history consisting of asource system identifier and time of day will be discussed. FIG. 34 isan illustration to show an example of the format of information wheninformation is provided with a distribution history in the seventhembodiment of the information processing system of the invention. Tohold a distribution history in information, a history informationholding section is provided in an information label section ofinformation stored on an information medium, as in the example shown inFIG. 34. When information is recorded on an information medium, adistribution history consisting of the source system identifier and thetime of day is written into the history information holding section inthe information label section of the recorded information. At thedestination, where the information was distributed from can be known byseeing the distribution history recorded in the history informationholding section in the information label section of the information.

FIG. 35 is an illustration of an example of the information distributionoperation when information is provided with a distribution history inthe seventh embodiment of the information processing system of theinvention. Sections identical with or similar to those previouslydescribed with reference to FIG. 17 are denoted by the same referencenumerals in FIG. 35 and will not be discussed again. In FIG. 35, numeral26 designates an information medium. Information in the format as shownin FIG. 34 is recorded on the information medium 26.

When information is recorded on the information medium 26, adistribution sensing section 14 of the source system senses that theinformation is distributed to the information medium 26 and the sourceinformation intervention system writes a distribution history in theform

    "written by id-A at T1"

into the history information holding section of the information, whereid-A is the system identifier of the source information interventionsystem and T1 is the time of day.

When the information is distributed from the information medium 26 to adestination information intervention system, a distribution sensingsection 14 of the destination system senses that the information isdistributed from the information medium 26, and sees the distributionhistory recorded in the history information holding section of thedistributed information for knowing where the information is distributedfrom. Based on the known fact, for example, the distribution history

    "received id-X from id-A at T2"

is written into a distribution history holding section 15 of thedestination information intervention system. The subsequent operation issimilar to that in the second embodiment, for example.

After the information is received at the destination and the history isrecorded in the distribution history holding section 15 of thedestination system, the distribution history held in the historyinformation holding section of the information may be erased. However,if there is a possibility that it will be distributed to anotherinformation intervention system, the distribution history may be leftintact until the information is erased.

Next, the method of providing an information medium with a historyinformation holding section for writing a distribution historyconsisting of a source system identifier and time of day will bediscussed. FIG. 36 is an illustration to show an example of the formatof information when an information medium is provided with adistribution history in the seventh embodiment of the informationprocessing system of the invention. To hold a distribution history in aninformation medium 26, a medium label section is provided in theinformation medium 26 and a history information holding section isprovided in the medium label section, for example, as shown in FIG. 36.When information is recorded on the information medium 26, adistribution history consisting of the information identifier, thesource system identifier, and the time of day is written into thehistory information holding section in the medium label section of theinformation medium 26. At the destination, the distribution historyrecorded in the history information holding section in the medium labelsection of the information medium 26 is seen, whereby where whichinformation was distributed from can be known.

FIG. 37 is an illustration of an example of the information distributionoperation when an information medium is provided with a distributionhistory in the seventh embodiment of the information processing systemof the invention. Sections identical with or similar to those previouslydescribed with reference to FIG. 35 are denoted by the same referencenumerals in FIG. 37. When information is recorded on an informationmedium 26, the distribution sensing section 14 of the source systemsenses that the information is recorded on the information medium 26 andthe source information intervention system writes, for example, thedistribution history

    "id-X was written by id-A at T1"

into the history information holding section of the information medium26, where id-X is the information identifier of the information, id-A isthe system identifier of the source information intervention system, andT1 is the time of day.

When the information is distributed from the information medium 26 to adestination information intervention system, the distribution sensingsection 14 of the destination system senses that the information isdistributed from the information medium 26, and sees the distributionhistory recorded in the history information holding section of theinformation medium 26 for knowing where the information is distributedfrom. For example, the distribution history

    "received id-X from id-A at T2"

is written into the distribution history holding section 15 of thedestination information intervention system. The subsequent operation issimilar to that in the second embodiment, for example.

In this method, information such as the information source systemidentifier is written into the distribution history holding section 15of the destination information intervention system. Then, to furtherrecord the information destination system identifier in the distributionhistory holding section of the source information intervention system,when information is received at the destination information interventionsystem, the destination information intervention system can also informthe source information intervention system of reception of theinformation. An example for this purpose is given below:

FIG. 38 is an illustration of an example of the information distributionoperation in an eighth embodiment of the information processing systemof the invention. Sections identical with or similar to those previouslydescribed with reference to FIG. 37 are denoted by the same referencenumerals in FIG. 38 and will not be discussed again. In FIG. 38, numeral27 designates a distribution information notification section. Theeighth embodiment assumes that information is distributed as with thecase where an information medium is provided with a distribution historyin the seventh embodiment.

The distribution information notification section 27 transfersinformation to and from distribution information notification sections27 of other information intervention systems. It can see a distributionhistory recorded in a history information holding section of aninformation medium 26 for knowing where the information is distributedfrom. Then, the distribution information notification section 27notifies the source information intervention system of reception of theinformation. The distribution information notification section 27 of thesource information intervention system receives the informationreception notification from the distribution information notificationsection 27 of the destination information intervention system and storesa distribution history in a distribution history holding section 15.

Now, assume that information is distributed from an information medium26 to a destination. As in the seventh embodiment, when the informationis distributed from the information medium 26 to the destinationinformation intervention system, a distribution sensing section 14 ofthe destination system senses that the information is distributed fromthe information medium 26, and writes, for example, the distributionhistory

    "received id-X from id-A at T2"

into a distribution history holding section 15 of the destinationinformation intervention system. In the eighth embodiment, when sensingthat the information is distributed from the information medium 26, thedistribution sensing section 14 of the destination system records thedistribution history in the distribution history holding section 15 andnotifies the distribution information notification section 27, whichthen sees the distribution history recorded in the history informationholding section of the information medium 26 for knowing where theinformation is distributed from, and notifies the source informationintervention system of reception of the information.

Since the source information intervention system can know theinformation destination from the notification from the destinationsystem, the distribution information notification section 27 receivingthe notification writes, for example, the distribution history

    "sent id-X to id-B at Ti"

into the distribution history holding section 15 of the sourceinformation intervention system. In this case, as in the thirdembodiment, the distribution information is stored in both the sourceand destination systems. Thus, the subsequent operation is similar tothat in the third embodiment.

In the eighth embodiment, without writing a distribution history intothe distribution history holding section 15 of the destinationinformation intervention system, the distribution informationnotification section 27 notifies the source information interventionsystem of reception of information and the distribution history can alsobe held in the distribution history holding section 15 of the sourceinformation intervention system. In this case, the distribution historyis stored in the source system, as in the first embodiment. By using theeighth embodiment, even if information is distributed to a number ofinformation intervention systems via an information medium 26, itsdistribution histories are stored in the source system. In this case,the subsequent operation is similar to that in the first embodiment.

In the seventh and eighth embodiments, preparation histories can also beheld, information identifiers can also be calculated from informationmain bodies, or user identifiers can also be used as in the fourth tosixth embodiments.

The embodiments assume that if information is distributed between theinformation intervention systems, the information identifier does notchange when the information is not modified. However, the invention isnot limited to it. The invention can also be embodied so that wheneverinformation is distributed between the information intervention systems,the information identifier is changed for preventing the informationhaving identical information identifiers from existing. In this case, aninformation identifier change history may be stored in the distributionhistory holing section 15 together with a distribution history.

In the embodiments, the three information pieces of the time of day,destination or source system identifier, and information identifier areused as a distribution history, but the invention is not limited tothem. For example, if time information is not required, the time of dayneed not be recorded. Both system and user identifiers may be recordedso as to trace a detailed distribution route as to information wasdistributed from what user in what information intervention system towhat user in what information intervention system.

Further, in the embodiments, a distribution history is stored in thedistribution history holding section of an information interventionsystem, but the invention is not limited to it. For example, informationmay be provided with a portion for holding a distribution history apartfrom the information main body so that time information, a modificationhistory, and the like are stored in the distribution history holdingsection of the information.

In the embodiments, the analysis result is only displayed. However, howthe analysis result is used is not limited. The analysis result can beused in various manners; for example, such a component using theanalysis result for automatically sending additional information to thepersons receiving one information may be added.

As seen from the description made so far, according to the invention,when information is distributed, a distribution history is recorded andthe recorded histories are analyzed, whereby distribution information ofthe information distribution route, distribution range, distributionamount, etc., can be traced later. Tracing in a wider range is enabledby recording not only distribution histories, but also informationpreparation and use histories. Since the invention can be used to locatethe information distribution route and distribution range, thedistributor and distribution route of illegal information can belocated, for example. The invention can be applied to distribution ofall digitalized information such as texts, images, voice, and programs.

What is claimed is:
 1. An information tracing systemcomprising:distribution sensing means for sensing informationdistribution from a first information processing system as aninformation distribution source to a second information processingsystem as an information distribution destination; a plurality ofdistribution history storing means for storing histories related toinformation distribution sensed by said distribution sensing means;history acquiring means for acquiring the histories stored in otherdistribution history storing means in response to the history stored inone of said distribution history storing means; and analyzing means foranalyzing an information distribution route in response to the historiesacquired by said history acquiring means.
 2. An information tracingsystem as claimed in claim 1, wherein when information is sent from thefirst information processing system, said distribution sensing meanssenses an information sending to sense information distribution.
 3. Aninformation tracing system as claimed in claim 1, wherein wheninformation is received at the second information processing system,said distribution sensing means senses an information reception to senseinformation distribution.
 4. An information tracing system as claimed inclaim 1, wherein when information is sent from the first informationprocessing system, said distribution sensing means senses theinformation sending, and when information is received at the secondinformation processing system, said distribution sensing means sensesthe information reception, to sense information distribution.
 5. Aninformation tracing system as claimed in claim 1 furthercomprising:editing means for editing information; edit sensing means forsensing edit executed by said editing means; and edit history storingmeans for storing histories related to edit sensed by said edit sensingmeans; wherein said history acquiring means acquires the historiesstored in said distribution history storing means and the historiesstored in said edit history storing means; and said analyzing meansanalyzes a distribution route and information change in response to thehistories acquired by said history acquiring means.
 6. An informationtracing system as claimed in claim 1, wherein the distributedinformation contains an information label which is a label for theinformation; andsaid distribution history storing means stores theinformation label as a history related to distribution.
 7. Aninformation tracing system as claimed in claim 1, wherein said secondinformation processing system further comprising:information labelpreparing means being responsive to distributed information forpreparing an information label which is a label for the information;wherein said distribution history storing means stores the informationlabel prepared by said information label preparing means as a historyrelated to distribution.
 8. An information tracing system as claimed inclaim 1, wherein when information stored on an information recordingmedium is distributed, said distribution sensing means senses theinformation distribution, and whereinsaid distribution history storingmeans stores a history related to the information together with theinformation and a medium label which is a label for the storage mediumon the information recording medium.
 9. An information tracing system asclaimed in claim 8, wherein said distribution history storing meansstores a history related to the information together with theinformation and a medium label which is a label for the storage mediumon the information recording medium and stores the history related tothe information and the medium label which is the label for the storagemedium on a storage in said second information processing system towhich the information is distributed.
 10. An information tracing systemas claimed in claim 9 further comprising distribution informationnotifying means for sending a history from a distribution destination toa distribution source after said distribution sensing means sensesinformation distribution from the information storage medium.
 11. Aninformation tracing method comprising the steps of:sensing informationdistribution from a first information processing system as aninformation distribution source to a second information processingsystem as an information distribution destination; storing a historyrelated to the sensed information distribution in a storage of saidsecond information processing system; in response to the history storedon the storage in said second information processing system, acquiringthe histories stored on storage in other information processing systems;and analyzing an information distribution route in response to theacquired histories.